1. Field of the Invention
The present invention relates to a method for the production of a filled metering pump arrangement. More particularly, the method includes the steps of filling a product capable of flow into a film bag that is accommodated in a container, subsequently closing the film bag and the container by means of a pump that can be activated manually, which blocks a fluid connection between an outlet opening connected with the surroundings and the interior of the film bag, in the unstressed state, by means of at least one kick-back valve, and removing the gases situated in the film bag, at least approximately completely. Furthermore, the present invention relates to the use of such a metering pump arrangement.
2. The Prior Art
A dispensing device for fluids is known from DE 101 08 486 A1, with which liquid pharmaceuticals or cosmetics, for example, can be dispensed from a container in metered manner. The metering pump used for this purpose works without air equalization, whereby the fluid is accommodated within the container within an inner bag that is sealed relative to the surroundings, which bag collapses as it empties.
After such inner bags have been filled with fluids such as pharmaceuticals or cosmetics, residual air usually remains in the inner bag at first. However, this arrangement is undesirable for various reasons. For example, the oxygen is constantly in contact with the fluid during storage, which results in a reduction of the possible storage period or of the absence of germs in the fluid. It is true that this problem could be solved by filling the fluid container in a germ-free atmosphere or under inert gas, but because filling under such circumstances is very complicated and expensive, this method is not suitable for economically efficient production of metering pumps.
Furthermore, complete emptying of the bag is possible only if no residual air remains in the inner bag after it has been filled. The residual air in the inner container also has a disruptive effect if the dispensing device is not held straight, i.e. with the pump vertically on top, during activation. Thus, if the metering pump arrangement is not oriented completely vertically, residual air can be drawn in by the pump, and dispensed from the inner bag in place of the fluid. This requirement is particularly undesirable when administering medications, such as nose, eye or ear sprays. Holding the dispensing device precisely vertically for such applications is possible only with difficulties.
It is therefore proposed in DE 101 08 486 A1 to form a passage for the residual air to be drawn off, between the outer wall of the piston and the inner wall of the pressure cylinder of the metering pump. This passage connects with the inner bag, on the one hand, via an opening provided on the pump housing, and with the surroundings, on the other hand, via a valve-like flap within the pump. Any residual air remaining in the inner bag after it has been filled can be drawn off through this channel within the pump, in order to avoid the disadvantages mentioned above. However, forming this channel for the residual air in the inner bag presumes great precision in the production of the pump. Furthermore, the production of this known dispensing device is made more expensive by the complicated structure of the pump. With this known dispensing device, the metering pump projects into the inner bag with its pressure cylinder and its intake opening that is assigned to the kick-back valve on the inner bag side.
The valve in the dispensing head of this known dispensing device is formed so that it opens when the product to be dispensed flows out of the pump into the dispensing head under pressure, but is held closed via a spring as long as the product does not displace a sealing body counter to the spring pressure. As a results no residual air can be drawn towards the outside via this dispensing head. Drawing off the residual air is consequently possible only when the dispensing head has not yet been set onto the pump. However, this feature has the disadvantage that residual air always remains in the dispensing head, and this air must be removed from the dispensing head by a user, before first-time use, by means of activating the pump, before the product can be dispensed. Because air is compressible, and only small amounts of the product, for example approximately 28 mg, are dispensed with one pump stroke for the application of medications, for example, many pump strokes are often required for this application, which users consider unsatisfactory.